An integrated circuit may be formed by growing epitaxial semiconductor material in source/drain regions of one polarity of MOS transistor. The epitaxially grown material may be blocked from an opposite polarity MOS transistor by a hard mask of dielectric material. Patterning the hard mask prior to the epitaxial growth and removing the hard mask after the epitaxial growth without damaging or consuming underlying layers may be problematic. Maintaining a desired consistency of spacing between the epitaxial semiconductor material in source/drain regions of a transistor may also be problematic.